This is not really true with platforms like the iPhone, which support OpenGL ES 2.0. If you're talking about a AAA iPhone game -- sure, you will need to design

This is not really true with platforms like the iPhone, which support OpenGL ES 2.0. If you're talking about a AAA iPhone game -- sure, you will need to design specifically for the exact specs of the device. However, if you are porting a game that does not require absolutely 100% of the iPhone's capabilities, I think you would be surprised how easy it is to cross compile, for example, Black Shades for the iPhone.